Televisions incorporate a host of technologies to enable a viewer to watch programming from a variety of sources. These sources include terrestrial broadcast sources of analog (using National Television System Committee, or NTSC, format) and digital (using Advanced Television System Committee, or ATSC, format) TV signals. ATSC signals typically use video compression known as Motion Picture Experts Group (MPEG-2) and TVs must consequently support MPEG-2 decompression if they support ATSC programming.
Cable-provided “basic” television programming can also be provided in NTSC or quadrature amplitude modulation (QAM) format. Cable-provided “enhanced” programming may also be provided using high definition multimedia interface (HDMI) principles. Likewise, satellite-provided TV signals may be received in HDMI. As well, video from the Internet can be displayed on many modem TVs in a variety of formats, including data over cable service Internet specification (DOCSIS) format. Furthermore, TVs are often configured to support multiple audio formats, including advanced audio coding (AAC), Audio code 3 (AC3), digital theater system (DTS), and so on. And as contemporary viewers know, TVs are expected to support the presentation of electronic program guides (EPGs).